Choristodera

Champsosaurus lived from the Late Cretaceous to early Eocene in North America

• Europe
• Asia
• North America

The Choristodera are aquatic living, crocodile -like, extinct diapside reptiles that lived from the Upper Triassic to early Miocene in Europe, Asia and North America.

The animals had the fish eaters typical, strongly elongated snout, as it occurs in convergent Gavial about today. Among the characteristics of their skull anatomy includes the relocation of the original upper of the two diapsiden temporal window behind the lower and the strong lateral widening of the zygomatic arches. This adjustment in the cranial structure served a strong jaw muscles to accommodate. The ribs were thickened by the Choristodera Pachyostose. Her limbs were only weakly ossified, a sternum was missing. Probably the animals swam like modern crocodiles, meandering through movements of the body and tail, and docked with the body legs. The largest Choristodera were three feet long.

Some Choristodera survived the mass extinction at the Cretaceous - Tertiary boundary and a recently discovered species of the genus in the Czech Republic Lazarussuchus seems to have been alive in the early Miocene.

System

The systematic position of the Choristodera is uncertain. Imagined one they used to Lepidosauromorpha, so you think today that they belonged to the Archosauromorpha as a primitive, with the archosaurs distantly related group.

• Choristodera Irenosaurus ( Efimov, 1983)
• Khurendukhosaurus Sigogneau Russell & Efimov, 1984
• Lazarussuchus Hecht, 1992; Upper Oligözän - early Miocene
• Cteniogelys Gilmore, 1928; Middle - Upper Jurassic
• Monjurosuchidae Endo, 1940 Philydrosaurus Gao & Fox, 2005; lower Cretaceous
• Monjurosuchus Endo, 1940; lower Cretaceous

• Shokawa Evans & Manabe, 1999
• Hyphalosaurus Gao, Tang & Wang, 1999 Lower Cretaceous

• Simoedosauridae Lemoine, 1884 Tchoiria Efimov, 1975
• Ikechosaurus Sigogneau Russell, 1981
• Simoedosaurus Gervais, 1877

• Eotomistoma
• Champsosaurus Cope, 1876